Some States offer local governments control over alcohol policy development and enforcement. Other States control alcohol policy at the State government level. Even with this flexibility for the States, Congress retains the power to use financial and tax incentives to promote certain alcohol policies, such as the minimum legal drinking age. The Federal Uniform Drinking Age Act of 1984 sets the minimum legal drinking age to 21 and every State abides by that standard. According to this Act, the Federal government can withhold ten percent of Federal funding for highways from States that do not prohibit people under age 21 from buying or publically possessing any alcoholic beverage.  While every State abides by this standard, State law varies on specifics about possession and exceptions to the law, such as allowing people under 21 to drink with their parents.